In light of the increasing amounts of crude oil shipped by rail, Pennsylvania Gov. Tom Wolf penned a letter to President Barack Obama demanding stricter crude-by-rail safety and enforcement standards.

Citing the 2014 Lac-Megantic, Quebec, tragedy as well as several recent derailments in the United States, Wolf made a case for greater federal safety standards across the board. He requested a reevaluation of rail speed limits in high-density areas, stricter standards for tank cars and train braking systems, and increased federal assistance in hiring and training more rail safety inspectors.

He also asked that Bakken oil be treated to remove dangerous volatiles prior to shipping.

"The potential for disaster is too great to ignore," Wolf wrote in the letter. "In my first weeks in office, I have made it a top priority to address this issue. My administration has begun to take steps to increase safety and response capability regarding trains traveling through Pennsylvania."

To that end, Wolf has planned meetings with executives at Norfolk Southern Railway and CSX Corp. to brainstorm ways to decrease the risk of derailments and accidents.

Rail safety standards have also not kept pace with current shipment levels, Wolf said. He asked for a greater sense of urgency in creating and implementing new federal safety standards.